Using Diary Methods to Study Marital and Family Processes.

Diary methods allow researchers to study marital and family processes within the context of daily life in a way that is not possible with more traditional methods. The authors review applications of diary designs in marital and family research and detail the types of research questions that can uniquely be asked of dyadic/family diary data. Technological developments for the use of electronic palm-top devices for implementing diary methods are also reviewed. Additionally, the authors discuss specific issues relevant to the analysis of diary data that come from dyads or families. Last, the authors raise unresolved issues and directions for future research in the use of diary methods for studying marital and family processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced magnetic field sensitivity of spin-dependent transport in cluster-assembled metallic nanostructures

The emerging field of spintronics explores the many possibilities offered by the prospect of using the spin of the electrons for fast, nanosized electronic devices. The effect of magnetization acting on a current is the essence of giant or tunnel magnetoresistance. Although such spintronics effects already find technological applications, much of the underlying physics remains to be explored. The aim of this article is to demonstrate the importance of spin mixing in metallic nanostructures. Here we show that magnetic clusters embedded in a metallic matrix exhibit a giant magnetic response of more than 500% at low temperature, using a recently developed thermoelectric measurement. This method eliminates the dominating resistivity component of the magnetic response and thus reveals an intrinsic spin-dependent process: the conduction-electron spin precession about the exchange field as the electron crosses the clusters, giving rise to a spin-mixing mechanism with strong field dependence. This effect appears sensibly only in the smallest clusters, that is, at the level of less than 100 atoms per cluster.     

Interleukin-1 in multiple myeloma: producer cells and their role in the control of IL-6 production

We studied the role of interleukin (IL)-1beta in patients with multiple myeloma. By in situ hybridization and immunochemistry, myeloid and megakaryocytic cells expressed high levels of the IL-1beta gene and produced IL-1beta. Myeloma cells less potently expressed the IL-1beta gene and IL-1beta protein. IL-1beta gene expression was not constitutive since it was detected in the bone marrow myeloma cells of two patients, unlike circulating tumoural cells. In addition, nine myeloma cell lines failed to express the IL-1beta gene and this expression could not be induced by 12 different cytokines. We demonstrated that IL-1 was mainly responsible for IL-6 production in the tumoural environment through a PGE2 loop. In fact, an IL-1 receptor antagonist (IL-1RA) blocked PGE2 synthesis and IL-6 production by 80%; this blockage could be reversed by adding synthetic PGE2. Similar findings were found with indomethacin, an inhibitor of cyclooxygenase that blocks PGE2 synthesis. Taken together, these data emphasize the possibility of blocking IL-1 by using IL-1RA or other antagonists in order to block IL-6 production, which is a major tumoural survival and proliferation factor.     

Haloacetic acid and trihalomethane formation from the chlorination and bromination of aliphatic beta-dicarbonyl acid model compounds

While it is known that resorcinol- and phenol-type aromatic structures within natural organic matter (NOM) react during drinking water chlorination to form trihalomethanes (THMs), limited studies have examined aliphatic-type structures as THM and haloacetic acid (HAA) precursors. A suite of aliphatic acid model compounds were chlorinated and brominated separately in controlled laboratory-scale batch experiments. Four and two beta-dicarbonyl acid compounds were found to be important precursors for the formation of THMs (chloroform and bromoform (71-91% mol/mol)), and dihaloacetic acids (DXAAs) (dichloroacetic acid and dibromoacetic acid (5-68% mol/mol)), respectively, after 24 h at pH 8. Based upon adsorbable organic halide formation, THMs and DXAAs, and to a lesser extent mono and trihaloacetic acids, were the majority (> 80%) of the byproducts produced for most of the aliphatic beta-dicarbonyl acid compounds. Aliphatic beta-diketone-acid-type and beta-keto-acid-type structures could be possible fast- and slow-reacting THM precursors, respectively, and aliphatic beta-keto-acid-type structures are possible slow-reacting DXAA precursors. Aliphatic beta-dicarbonyl acid moieties in natural organic matter, particularly in the hydrophilic fraction, could contribute to the significant formation of THMs and DXAAs observed after chlorination of natural waters.     

Unsaturated zone arsenic distribution and implications for groundwater contamination

Arsenic compounds have been applied at the land surface as pesticides in agricultural areas globally. The purpose of this study was to evaluate the fate of anthropogenic arsenic applications related to agriculture, using arsenic applications on cotton in the southern High Plains (SHP), Texas, as a case study and examining possible linkages with contamination of the underlying Ogallala aquifer in this region, where 36% of wells exceed the new EPA 10 microg/L standard. Unsaturated zone soil samples were collected from boreholes beneath natural ecosystems (grassland/ shrubland) to provide a control (no arsenic application) (5 profiles) and cotton cropland (20 profiles) for analyses of water-extractable arsenic, vanadium, phosphate, chloride, and nitrate. Natural ecosystem profiles have high arsenic concentrations at depth (maximum of 7.2-69.6 microg As/ kg dry soil at 5.9-21.4 m depth) that are attributed to a geologic source. Most profiles beneath cotton cropland have high arsenic concentrations within the upper meter (profile means 1.7 to 31.6 microg/kg) that correlate with phosphate (r = 0.70, p < 0.01) and are attributed to anthropogenic arsenic application associated with phosphate fertilizer application. High arsenic concentrations at >1 m depth (profile means < or =36.3 microg/kg) found in cropland profiles are attributed to a geologic source because of similarity with profiles beneath natural ecosystems, lack of correlation with phosphate, and pore-water ages that predate anthropogenic arsenic application in many profiles. GIS analyses showed poor correlations between groundwater arsenic and percent cultivated land (r = -0.15, p < 0.01), groundwater nitrate (r = 0.30, p < 0.01), and water table depth (r= -0.31, p < 0.01), further supporting the idea that anthropogenic-derived arsenic in the shallow subsurface is not linked to groundwater arsenic contamination in this region.     

Shallow Subsurface Characterization of Gas Transport in a Playa Wetland

Controls on vadose-zone gas transport beneath and adjacent to a southern High Plains ephemeral lake (playa) were investigated. Under dry conditions, vertical gas permeability and tortuosity were enhanced by cracks and root tubules in the upper 2.5 m. Below this depth, the horizontal components of both permeability and tortuosity tensors were dominant. Both atmospheric pumping and pneumatic tests were used to determine the gas permeability tensor; whereas gas tracer tests were used to estimate the tortuosity tensor. The field data were elevated in a multilayer numerical model. The results suggest that gas movement can be dominated by both advection and diffusion, with vertical movement dominating in the shallow zone under dry conditions. After a large precipitation event, vertical gas permeability was reduced and large pressure differentials (as high as 1.5 kPa) were produced, creating driving forces for advective gas transport.     

Single-drop agglomeration of fine mineral admixtures for concrete and water requirement of pastes

This paper deals with water requirement determination of fine mineral admixtures for concrete by a simple and rapid test based on “single-drop” agglomeration. Eighteen fine and very fine mineral admixtures for concrete, different in origin and characteristics are tested. The influence of cement and high-range water-reducing admixtures are also studied. The “single-drop” test results are compared with standard tests proposed in concrete technology. The water–fine mineral admixture ratio of the formed agglomerate is proportional to the water requirement of the mineral admixture determined by the standard tests for concrete mixtures. However, the frictional forces between particles are not taken into account by the “single-drop” test and consequently the dispersing effect of high-range water-reducing admixtures. Round- and angular-shaped particles present a linear function between the water–fine mineral ratio and fineness, which is determined by the BET specific surface area or the average particle size of the minerals. Irregular-shaped particles present two to three times higher water–fine mineral ratio than that of round-shaped particles with equivalent fineness. In this case, the very low granular packing of mixtures exclude any use in concrete. When there is low cement content, the water–fine mineral-plus-cement ratio and consequently the porosity of binary blended mixtures increase significantly because of interaction phenomena between cement particles and water.     

Integrated synthetic, pharmacological, and computational investigation of cis-2-(3,5-dichlorophenylcarbamoyl)cyclohexanecarboxylic acid enantiomers as positive allosteric modulators of metabotropic glutamate receptor subtype 4

2‐(3,5‐Dichlorophenylcarbamoyl)cyclohexanecarboxylic acid ( 1 ) is a potent and selective positive allosteric modulator of metabotropic glutamate receptor subtype 4 (mGluR4). The activity of 1 was reported to reside in the cis diastereomer with equal potency between its enantiomeric forms (Niswender et al., Mol. Pharmacol. 2008 , 74, 1345–1358). In the present study, the asymmetric synthesis of each of the cis enantiomers was performed, and their activities were compared with that of the racemic trans. In our assays, the cis enantiomers differ in potency, with one of them (1R,2S) higher and the other (1S,2R) lower than the racemic trans. High‐level quantum chemical calculations were carried out to characterize the structures of minimum energy in all‐isomer conformational space as well as particular intermediates between conformational transitions. Computational analysis identified structural features of 1 that can play a role in mGluR4 functionality and establish the basis for subsequent work, in which molecular chirality constructed on conformations derived from those found for the active (1R,2S) enantiomer can provide new ideas for drug discovery. Comparison between experimental and theoretical circular dichroism spectra confirmed both the absolute configuration of the (1R,2S) compound and its calculated most stable conformation, thereby supporting experimental and theoretical work.